In gas turbines, the cooling air for cooling the interior of the shroud retained by a casing, flows into the shroud inserted between the casing and turbine gas path section to insulate the casing from heat in the gas path section that causes high temperatures.
The technology disclosed in a publicly known example of Japanese Unexamined Patent Application Publication No. Sho61 (1986)-118506 describes a gas turbine shroud structure comprised of a segmented type outer shroud installed on a casing segmented horizontally into two pieces, and an inner shroud facing the gas turbine section held on the inner circumferential side of the segmented type outer shroud. This structure is configured so that the cooling air to cool the inner shroud passes along the outer shroud and is guided into the inner shroud.
The technology for the gas turbine shroud structure disclosed in Japanese Unexamined Patent Application Publication No. Sho61(1986)-118506 is a structure as shown in FIG. 2 containing M type cross sectional seal members respectively mounted in the gap between on the side surfaces of the inner shroud, and the side surfaces of each segmented type outer shroud facing the side surfaces of this inner shroud in order to prevent the cooling air from escaping during passage along the cooling air passage.